Device for torque vectoring

ABSTRACT

A torque vectoring apparatus may include a first planetary gear set including first to third rotation elements, wherein the first rotation element is gear-connected to receive power from the speed reduction device, the second rotation element is connected to be configured for transmitting power to the differential, and the third rotation element is selectively connectable to a housing through a coupling element; a second planetary gear set including fourth, fifth, and sixth rotation elements, wherein the fifth rotation element is fixedly connected to the third rotation element; and a third planetary gear set including seventh, eighth, and ninth rotation elements, wherein the seventh rotation element is fixedly connected to the fourth rotation element, the eighth rotation element is fixedly connected to one of the left and right output shafts while being fixedly connected to the sixth rotation element, and the ninth rotation element is fixedly connected to the housing.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No.10-2017-0169585 filed on Dec. 11, 2017, the entire contents of which isincorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a torque vectoring apparatus. Moreparticularly, the present invention relates to a torque vectoringapparatus which is applied to a high-performance environmental vehiclesuch as a 1 motor e-AWD (All Wheel Drive) and the like to improveturning performance.

Description of Related Art

In general, a torque vectoring apparatus is a device that canindependently and freely control torque transmitted to left and rightwheels to improve agility and handing performance of a vehicle.

Here, the term “torque vectoring” refers to the magnitude and adirection of an output or driving torque of an engine transmitted towheels from a vehicle, and implies a technology for changing themagnitude and direction of the torque transmitted to the wheels, and inparticular, the torque transmitted to both wheels on the same axle axis.

That is, the torque vectoring differentiates the magnitude and directionof torque transmitted to both wheels, and is applied as an additionalfunction to a differential which varies a torque ratio of torquedistributed to the left and right wheels depending on a load applied tothe wheels.

The torque vectoring apparatus configured for such a function activelycontrols a function of the differential to apply a driving intention ofa driver such that a torque ratio divided into the left and right wheelsmay be controlled.

Accordingly, the driver can more actively utilize a driving torque andcan expect improvement of handling characteristics.

However, it is not easy to implement it technically because the torquevectoring apparatus needs to be configured for delivering an appropriatelevel of torque to a required wheel as needed, while maintaining basicfunctions of the differential.

Recently, as electric vehicle technology that can more accuratelyimplement torque vectoring according to alignment and control of a motorthan a driving system using an internal combustion engine has beendeveloped, the research and development of the torque vectoringapparatus is actively proceeding. In particular, with progress of highperformance of environmental vehicles, research and development aselement technology for improving turning performance of a highperformance environmental vehicle have been actively applied to a reardifferential of an AWD (All Wheel Drive) vehicle such as an electricvehicle (EV).

In a case of such an environmental vehicle, unlike a conventionalinternal combustion engine vehicle, a mechanical element such as atransfer shaft is not required. In the ease of a two-motor e-AWD andelectric vehicle, torque vectoring may be implemented by applying motorcontrol technology. However, in the case of 1-motor B-AWD, it isrequired to develop various torque vectoring technologies for achievingimprovement of turning performance by optimizing rear wheel powerdistribution.

The information disclosed in this Background of the Invention section isonly for enhancement of understanding of the general background of theinvention and may not be taken as an acknowledgement or any form ofsuggestion that this information forms the prior art already known to aperson skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing ahigh-performance environment vehicle such as a 1-motor e-AWD (All WheelDrive) vehicle to minimize torque loss, improving fuel economyperformance and turning performance.

Furthermore, the torque vectoring apparatus according to the exemplaryembodiment of the present invention is directed to providing a torquevectoring apparatus that can maintain durability of a device source andreduce power loss by disconnecting a power connection state of the drivesource through a speed reduction device.

Furthermore, the torque vectoring apparatus according to the exemplaryembodiment of the present invention can minimize the loss of operationoil by inhibiting operation when the torque vectoring function such asturning is required by applying one coupling element to the torquevectoring apparatus, and the coupling element is released or appliedonly when straight traveling or when torque vectoring control isunnecessary and thus it is advantageous in terms of control andefficiency.

A torque vectoring apparatus according to one or a plurality ofexemplary embodiments of the present invention utilizes amotor/generator as a power source and may include a speed reductiondevice reducing rotational power of the motor/generator, a differentialthat transmits rotational power transmitted from the speed reductiondevice while absorbing a rotation speed difference between left andright wheels, and a torque vectoring apparatus that adjust a torqueratio of torque distributed to the left wheel and the right wheel, andis disposed on left and right output shafts that are power-connected tothe differential. The torque vectoring apparatus may include: a firstplanetary gear set that may include first, second, and third rotationelements, wherein the first rotation element is gear-connected toreceive power from the speed reduction device, the second rotationelement is connected to be configured for transmitting power to thedifferential, and the third rotation element is selectively connectableto a housing through a coupling element; a second planetary gear setthat may include fourth, fifth, and sixth rotation elements, wherein thefifth rotation element is fixedly connected to the third rotationelement; and a third planetary gear set that may include seventh,eighth, and ninth rotation elements, wherein the seventh rotationelement is fixedly connected to the fourth rotation element, the eighthrotation element is fixedly connected to one of the left and rightoutput shafts while being fixedly connected to the sixth rotationelement, and the ninth rotation element is fixedly connected to thehousing.

The coupling element may be formed of a brake which is provided betweenthe third rotation element and the housing and may operate the thirdrotation element as a selective fixing element.

The first planetary gear set may be formed of a single pinion planetarygear set and thus the first, second, and third rotation elements arerespectively provided as a first linear gear, a first planet carrier,and a first ring gear, the second planetary gear set may be formed of asingle pinion planetary gear set and thus the fourth, fifth, and sixthrotation elements are respectively provided as a second linear gear, asecond planet carrier, and a second ring gear, and the third planetarygear set may be formed of a single pinion planetary gear set and thusthe seventh, eighth, and ninth rotation elements are respectivelyprovided as a third linear gear, a third planet carrier, and a thirdring gear.

The speed reduction device may include: a driving gear which isconnected to a rotor of the motor/generator through a hub; a driven gearformed in the first rotation element of the torque vectoring apparatus;and an idle gear device configured formed for power transmission throughan idle shaft between the driving gear and the driven gear themotor/generator to reduce rotational power of the motor/generator andtransmit the reduced rotational power to the torque vectoring apparatus.

Here, the idle gear device may include: an idle shaft which is disposedparallel with the left and right output shafts; an idle input gear whichis provided on the idle shaft and externally gear-connected to thedriving gear; and an idle output gear which is fixedly connected on theidle shaft and externally gear-connected to the driven gear.

The idle gear device may further include a synchronizer which isprovided between the idle input gear and the idle shaft for selectivesynchronization of the idle input gear with the idle shaft whiledisposing the idle input gear to be rotatable on the idle shaft.

The methods and apparatuses of the present invention have other featuresand advantages which will be apparent from or are set forth in moredetail in the accompanying drawings, which are incorporated herein, andthe following Detailed Description, which together serve to explaincertain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a torque vectoring apparatus accordingto an exemplary embodiment of the present invention.

FIG. 2 is a lever diagram provided for description of torque vectoringoperation of the torque vectoring apparatus according to the exemplaryembodiment of the present invention.

It may be understood that the appended drawings are not necessarily toscale, presenting a somewhat simplified representation of variousfeatures illustrative of the basic principles of the invention. Thespecific design features of the present invention as disclosed herein,including, for example, specific dimensions, orientations, locations,and shapes will be determined in part by the particularly intendedapplication and use environment.

In the figures, reference numbers refer to the same or equivalent partsof the present invention throughout the several figures of the drawing.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of thepresent invention(s), examples of which are illustrated in theaccompanying drawings and described below. While the invention(s) willbe described in conjunction with exemplary embodiments of the presentinvention, it will be understood that the present description is notintended to limit the invention(s) to those exemplary embodiments. Onthe other hand, the invention(s) is/are intended to cover not only theexemplary embodiments of the present invention, but also variousalternatives, modifications, equivalents and other embodiments, whichmay be included within the spirit and scope of the invention as definedby the appended claims.

Hereinafter, an exemplary embodiment of the present invention will bedescribed in detail with reference to the accompanying drawings.

To clarify the present invention, parts that are not connected to thedescription will be omitted, and the same elements or equivalents arereferred to with the same reference numerals throughout thespecification.

In the following detailed description, the reason why terms such asfirst and second are used is to distinguish between elements because thefirst and the second elements respectively have the same constructions,and thus the elements are not limited to such order in the followingdescription.

FIG. 1 is a schematic diagram of a torque vectoring apparatus accordingto an exemplary embodiment of the present invention.

Referring to FIG. 1, a torque vectoring apparatus according to anexemplary embodiment of the present invention is formed of a speedreduction device 10 disposed on each of left and right output shafts OS1and OS2, a differential 20, and a torque vectoring apparatus 30,together with a motor/generator (MG), which is a driving source.

That is, the torque vectoring apparatus reduces rotational power of themotor/generator MG in the speed reduction device 10 and transmits thereduced torque to the torque vectoring apparatus 30, and the torquevectoring apparatus 30 transmits the received torque to the differential20.

As such, the differential 20 transmits rotational power transmitted fromthe torque vectoring apparatus 30 to left and right wheels whileabsorbing a speed difference between the left and right wheels.

In the instant case, the torque vectoring apparatus 30 improves drivingperformance such as turning performance and the like by adjusting atorque ratio divided into the left wheel and the right wheel accordingto driving conditions such as turning performance and the like.

The left and right output shafts OS1 and OS2 are power transmissionshafts provided between the differential 20 and the left and rightwheels, and may imply typical left and right driveshafts.

The motor/generator MG is formed of a stator ST fixed to one side of ahousing H and a rotor RT power-connected to the speed reduction device10, and may simultaneously perform a function of a motor that suppliesrotational power to the speed reduction device 10 and of a generatorthat generates electricity while rotating by the torque transmitted fromthe left and right wheels.

The speed reduction device 10 reduces rotational power transmitted fromthe motor/generator MG and transmits the reduced torque to the torquevectoring apparatus 30.

The speed reduction device 10 includes a drive gear DG, a driven gearPG, and an idle gear device IDGU. That is, rotational power of themotor/generator MG, transmitted through the drive gear DG is reducedthrough the idle gear device IDGU and the reduced torque is transmittedto the torque vectoring apparatus 30 through the driven gear PG.

The drive gear DG is connected to the rotor RT of the motor/generator MGin a fixed manner through a hub 3.

The driven gear PG is formed on one rotation element of the torquevectoring apparatus 30, and transmits rotational power of themotor/generator MG to the torque vectoring apparatus 30.

The idle gear device IDGU reduces the rotation power of themotor/generator MG through two idle gears that are provided on an idleshaft IDS to transmit power between the drive gear DG and the drivengear PG, and transmits the reduced rotational power to the torquevectoring apparatus 30.

That is, the idle shaft IDS is disposed parallel with the left and rightoutput shafts OS1 and OS2.

The two idle gears provided on the idle shaft IDS are formed as an idleinput gear IDG1 and an idle output gear IDG2.

The idle input gear IDG1 is provided on the idle shaft IDS and isexternal-gear-connected to the drive gear DG.

The idle output gear IDG2 is fixedly connected to the idle shaft IDS andis external-gear-connected to the driven gear PG.

In the instant case, the idle gear device IDGU selectively synchronizesthe idle input gear IDG1 to the idle shaft IDS by forming a synchronizerSL on the idle shaft IDS to connect or disconnect rotational power ofthe motor/generator MG, transmitted to the torque vectoring apparatus30.

That is, the synchronizer SL is disposed between the idle input gearIDG1 and the idle shaft IDS to selectively synchronize the idle inputgear IDG1 to the idle shaft IDS while forming the idle input gear IDG1to be rotatable about the idle shaft IDS.

Here, since the synchronizer SL is a known component, no furtherdetailed description will be provided, and a sleeve SLE applied to thesynchronizer SL is provided with an additional actuator or as is known,and the actuator may be controlled by a control device.

Meanwhile, the differential 20 may be provided as a typical differentialthat transmits rotational power transmitted from the torque vectoringapparatus 30 to the left and right output shafts OS1 and OS2 whileabsorbing a rotation speed difference between the left wheel and theright wheel.

The torque vectoring apparatus 30 is provided to adjust a torque ratiodivided to the left and right wheels, and is formed of a combination ofthree planetary gear sets PG1, PG2, and PG3.

The three planetary gear sets PG1, PG2, and PG3 are formed of a firstplanetary gear set PG1, a second planetary gear set PG2, and a thirdplanetary gear set PG3 that are disposed in parallel with each other atthe right side of the speed reduction device 10, and one rotationelement of the first planetary gear set PG1 operates as a selectivefixing element while being selectively connectable to a housing Hthrough a brake BK, which is a coupling element.

The first planetary gear set PG1 is a single pinion planetary gear setthat includes first, second, and third rotation elements N1, N2, and N3,and includes a first linear gear S1, which is the first rotation elementN1, a first planet carrier PC1, which is the second rotation element N2that supports a plurality of pinion gears P1 which are equispaced andradially outwardly engaged with an external circumferential side of thefirst linear gear P1 to be configured for rotation and revolution, and afirst ring gear R1, which is the third rotation element N3 and isinwardly engaged with the plurality of first pinion gears P1 and thuspower-connected to the first linear gear S1.

The second planetary gear set PG2 is a single pinion planetary gear setthat includes fourth, fifth, and sixth rotation elements N4, N5, and N6,and includes a second linear gear S2, which is the fourth rotationelement N4, a second planet carrier PC2, which is the fifth rotationelement N5 that supports a plurality of second pinion gears P2 which areequispaced and radially outwardly engaged with an externalcircumferential side of the second linear gear S2 to be configured forrotation and revolution, and a second ring gear R2, which is the sixthrotation element N6 and is inwardly engaged with the plurality of secondpinion gears N2 and thus power-connected to the second linear gear S2.

The third planetary gear set PG3 is a single pinion planetary gear set,and includes a third linear gear S3, which is a seventh rotation elementN7, a third planet carrier PC3, which is an eight rotation element N8and supports a plurality of pinion gears P3 which are equispaced andradially outwardly engaged with an external circumferential side of thethird linear gear S3, and a third ring gear R3, which a ninth rotationelement N9 which is inwardly engaged with the plurality of third piniongears P3 and thus is power-connected to the third linear gear S3.

In an exemplary embodiment of the present invention, the first lineargear S1, second linear gear S2, and third linear gear S3 are a first sungear, a second sun gear, and a third sun gear.

Here, the first rotation element N1 is outwardly engaged with the idleoutput gear IDG2 of the speed reduction device 10 through the drivengear PG, and receives speed-reduced rotational power of themotor/generator MG.

The second rotation element N2 is power-connected to the speeddifferential 20 through a first connection member CN1, and the thirdrotation element N3 is selectively connectable to the housing H throughthe brake BK, which is a coupling element, and thus is configured as aselective fixing element.

Furthermore, the third rotation element N3 is connected to the fifthrotation element N5 in a fixed manner through a second connection memberCN2, the fourth rotation element N4 is fixedly connected to the seventhrotation element N7 through a third connection member CN3, and the sixthrotation element N6 is fixedly connected to the eighth rotation elementN8 through a fourth connection member CN4.

Here, the eighth rotation element N8 is fixedly connected to theright-side output shaft OS2 through a fifth connection member CN5, andthe ninth rotation element N9 is connected to the housing H in a fixedmanner through a sixth connection member CN6.

The above-stated six connection members CN1 to CN6 may be rotationmembers that fixedly connect a plurality of rotation elements andtransmit power while rotating together with the rotation members,rotation members that selectively connect the rotation elements with thehousing H, or fixing members that directly connect and fix the rotationelements to the housing H among the rotation elements of the planetarygear sets PG1, PG2, and PG3.

Furthermore, the expression “fixedly connected” or a term similarthereto implies that the left and right output shafts OS1 and OS2 areincluded and a plurality of rotation elements and a correspondingconnection member connected through the corresponding connection memberrotate without a rotation speed difference. That is, the plurality offixedly connected rotation elements and the corresponding connectionmember rotate in the same rotation direction with the same rotationspeed.

Furthermore, in the above description, the expression “selectivelyconnectable” or terms similar thereto implies that the left and rightoutput shafts OS1 and OS2 are included and a plurality of rotationelements and a corresponding connection member connected through thecorresponding connection member rotate without a rotation speeddifference, or the corresponding connection member is fixed to thehousing through the coupling element.

That is, when the coupling elements selectively connect the plurality ofconnection members, the coupling elements operate such that theplurality of connection members rotate in the same direction with thesame rotation speed, and when the coupling elements are released, theconnection of the plurality of connection members is disconnected.

In the above description, each coupling element formed of the brake BKmay be provided as a hydraulic friction coupling device operated byhydraulic pressure supplied by a hydraulic control apparatus, and ingeneral, a multi-plate wet hydraulic friction coupling device is used,but may be provided as a coupling device which may operate depending onelectrical signals supplied from an electronic control apparatus, suchas a dog clutch, an electronic clutch, a magnetic clutch, and the like.

The torque vectoring apparatus 30 having such a configuration performstorque vectoring control with respect to torque transmitted to the leftand right wheels according to selective control of the brake BK as shownin a lever diagram of FIG. 2.

FIG. 2 is a lever diagram provided for description of torque vectoringoperation of the torque vectoring apparatus according to the exemplaryembodiment of the present invention.

Referring to (A), (B), and (C) in FIG. 2, the torque vectoring apparatusaccording to the exemplary embodiment of the present invention controlsa torque distribution ratio of torque transmitted to the left and rightwheels by selectively controlling the brake BK and controlling torque ofthe motor/generator MG, which is a driving source, according to adriving condition such as straight running, left or right turning, andthe like.

That is, referring to FIG. 2, the vertical axis denotes rotation speedof nine rotation elements N1 to N9 of the first, second, and thirdplanetary gear sets PG1, PG2, and PG3 of the torque vectoring apparatus30, and the horizontal axis denotes a gear ratio (number of gear teethof linear gear/number of gear teeth of ring gear) of each of therotation elements N1 to N9.

The vertical axis and the horizontal axis are known to a person in thefield of the planetary gear train, and therefore no further detaileddescription will be provided.

Torque vectoring operation according to the driving condition of thetorque vectoring apparatus will now be described with reference to thelever diagram of FIG. 2.

First, referring to FIG. 2, the third rotation element N3 is selectivelyconnectable to the housing H through the brake BK, the ninth rotationelement N6 is fixed to the housing H, and the first rotation element N1receives rotational power which is reduced while passing through thespeed rotation device 10.

[Straight Running]

Referring to (A) in FIG. 2, when the vehicle is in the straight runningcondition, the brake BK is controlled in an operation state.

As such, the third rotation element N3 is fixed to the housing H byoperation of the brake BK and thus functions as a fixing element, andthe second and third planetary gear sets PG2 and PG3 of the torquevectoring apparatus 30 do not affect rotation speed or torquedistribution of the right output shaft OS2.

Accordingly, rotational power, which was reduced through the speedreduction device 10 and input to the first rotation element N1 of thefirst planetary gear set PG1 which is in the torque vectoring apparatus30, from the motor/generator MG, equally acts on the left and rightoutput shafts OS1 and OS2 with the same torque through the secondrotation element N2, and in the instant case, torque is divided 50:50 tothe left and right output shafts OS1 and OS2 such that the vehicle canperform straight running.

[Left Turn Traveling]

Referring to (B) in FIG. 2, when the vehicle is turning left, operationof the brake BK is released, and a torque of the motor/generator MG iscontrolled to be “−”.

Accordingly, rotational power, which was reduced through the speedreduction device 10 and input to the first rotation element N1 of thefirst planetary gear set PG1 which is in the torque vectoring apparatus30, from the motor/generator MG, is output to the left and right outputshafts OS1 and OS2 through the second rotation element N2 such that therotation speed and a torque of the eighth rotation element N8 connectedto the right output shaft OS2 are increased.

When torque is distributed, the right output shaft OS2 that transmitsthe rotational power to the right wheel which is outside during the turnis distributed greater than the left output shaft OS1 to enable the leftturn traveling.

[Right Turn Traveling]

Referring to (C) in FIG. 2, when the vehicle is turning right, operationof the brake BK is released, and a torque of the motor/generator MG iscontrolled to be “+”.

Accordingly, rotational power, which was reduced through the speedreduction device 10 and input to the first rotation element N1 of thefirst planetary gear set PG1 which is in the torque vectoring apparatus30, from the motor/generator MG, is output to the left and right outputshafts OS1 and 0S2 through the second rotation element N2 such that therotation speed and a torque of the eighth rotation element N8 connectedto the right output shaft OS2 are decreased.

When torque is distributed, the left output shaft OS1 that transmits therotational power to the left wheel which is outside during the turn isdistributed greater than the right output shaft OS2 to enable the rightturn traveling.

While driving, when the vehicle speed is increased and thus rotationspeed of the motor/generator MG exceeds the maximum hardware-permissibleRPM, rotational power of the motor/generator MG is disconnected byasynchronous operation of the synchronizer SL provided in the speedreduction device 10 such that the motor/generator MG may be operatedwithout a load.

As described above, the torque vectoring apparatus according to theexemplary embodiment of the present invention is applied to ahigh-performance environmental vehicle such as a 1 motor e-AWD (AllWheel Drive) vehicle and the like to improve driving performing of thevehicle through torque vectoring according to a driving condition suchas turning performance.

Furthermore, when the vehicle speed is increased and thus rotation speedof the motor/generator MG exceeds the maximum hardware-permissible RPM,the motor/generator MG may be operated without a load by asynchronousoperation of the synchronizer SL such that durability of themotor/generator MG may be preserved, and rotational power of themotor/generator MG is disconnected to reduce unnecessary powerconsumption, improving fuel efficiency.

Furthermore, the rotational power disconnection function of themotor/generator MG may be effectively applied to disconnect rotationalpower of a driving motor in engine driving of a hybrid electric vehicle(HEV), a plug-in hybrid electric vehicle (PHEV), and the like.

Furthermore, it is possible to minimize the loss of operation oil byinhibiting operation when the torque vectoring function such as turningis required by applying one brake BK to the torque vectoring apparatus30, and the brake BK is released or applied only when straight travelingor when torque vectoring control is unnecessary and thus it isadvantageous in terms of control and efficiency.

For convenience in explanation and accurate definition in the appendedclaims, the terms “upper”, “lower”, “inner”, “outer”, “up”, “down”,“upper”, “lower”, “upwards”, “downwards”, “front”, “rear”, “back”,“inside”, “outside”, “inwardly”, “outwardly”, “internal”, “external”,“inner”, “outer”, “forwards”, and “backwards” are used to describefeatures of the exemplary embodiments with reference to the positions ofsuch features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of thepresent invention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteachings. The exemplary embodiments were chosen and described toexplain certain principles of the invention and their practicalapplication, to enable others skilled in the art to make and utilizevarious exemplary embodiments of the present invention, as well asvarious alternatives and modifications thereof. It is intended that thescope of the invention be defined by the Claims appended hereto andtheir equivalents.

What is claimed is:
 1. A torque vectoring apparatus that utilizes amotor/generator as a power source and includes a speed reduction devicereducing rotational power of the motor/generator, a differential thattransmits rotational power transmitted from the speed reduction devicewhile absorbing a rotation speed difference between first and secondwheels, and a torque vectoring apparatus that adjust a torque ratio oftorque distributed to the first wheel and the second wheel, and isdisposed on first and second output shafts that connected to thedifferential, wherein the torque vectoring apparatus comprises: a firstplanetary gear set that includes a first rotation element, a secondrotation element engaged to the first rotation element, and a thirdrotation element engaged to the second rotation element, wherein thefirst rotation element is engaged to the speed reduction device toreceive power from the speed reduction device, the second rotationelement is engaged to the differential for transmitting power to thedifferential, and the third rotation element is selectively connectableto a housing through a coupling element; a second planetary gear setthat includes a fourth rotation element, a fifth rotation elementengaged to the fourth rotation element, and a sixth rotation elementengaged to the fifth rotation element, wherein the fifth rotationelement is fixedly connected to the third rotation element; and a thirdplanetary gear set that includes a seventh rotation element, an eighthrotation element engaged to the seventh rotation element, and a ninthrotation element engaged to the eighth rotation element, wherein theseventh rotation element is fixedly connected to the fourth rotationelement, the eighth rotation element is fixedly connected to one of thefirst and second output shafts while being fixedly connected to thesixth rotation element, and the ninth rotation element is fixedlyconnected to the housing.
 2. The torque vectoring apparatus of claim 1,wherein the coupling element includes a brake which is mounted betweenthe third rotation element and the housing and selectively connects thethird rotation element to the housing.
 3. The torque vectoring apparatusof claim 1, wherein the first planetary gear set includes a singlepinion planetary gear set and the first rotation element, the secondrotation element, and the third rotation element are provided as a firstlinear gear, a first planet carrier, and a first ring gear,respectively, the second planetary gear set includes a single pinionplanetary gear set and the fourth rotation element, the fifth rotationelement, and the sixth rotation element are provided as a second lineargear, a second planet carrier, and a second ring gear, respectively, andthe third planetary gear set includes a single pinion planetary gear setand the seventh rotation element, the eighth rotation element, and theninth rotation element are provided as a third linear gear, a thirdplanet carrier, and a third ring gear, respectively.
 4. The torquevectoring apparatus of claim 1, wherein the speed reduction deviceincludes: a driving gear which is connected to a rotor of themotor/generator through a hub; a driven gear connected to the firstrotation element of the torque vectoring apparatus; and an idle geardevice including an idle shaft and configured for transiting rotationalpower of the motor/generator through the idle shaft between the drivinggear and the driven gear to reduce the rotational power of themotor/generator and to transmit the reduced rotational power to thetorque vectoring apparatus.
 5. The torque vectoring apparatus of claim4, wherein the idle gear device includes: the idle shaft which isdisposed parallel with the first and second output shafts; an idle inputgear which is rotatably mounted on the idle shaft and engaged to thedriving gear; and an idle output gear which is fixedly connected on theidle shaft and engaged to the driven gear.
 6. The torque vectoringapparatus of claim 5, wherein the idle gear device further includes asynchronizer which is mounted between the idle input gear and the idleshaft for selectively synchronizing of the idle input gear with the idleshaft.